WASHINGTON — U.S. wholesale businesses in January suffered their steepest sales drop in nearly five years, yet they continued to increase their stockpiles. This suggests that companies expect the economy to rebound after experiencing an abrupt winter slowdown.

Wholesalers boosted stockpiles 0.6 percent in January from December, the Commerce Department said Tuesday. Rising stockpiles boost economic growth because they reflect increased production at factories, a sign that wholesalers anticipate a stronger economy.

But sales tumbled 1.9 percent in January. That’s the largest decline since March 2009, when the economy was in recession.